using System;

using System.Diagnostics;

using System.Text.RegularExpressions;

using System.Globalization;

public class Program

{

    private static void Benchmark(Action act, int iterations)

    {

        GC.Collect();

        act.Invoke(); // run once outside of loop to avoid initialization costs

        Stopwatch sw = Stopwatch.StartNew();

        for (int i = 0; i < iterations; i++)

        {

            act.Invoke();

        }

        sw.Stop();

        Console.WriteLine((sw.ElapsedTicks).ToString());

    }

​

    public static void Main(string[] args)

    {

        Benchmark(() => { var result = new Program().PrivacyPolicyLocaleFormatIsInvalid("en-GB"); }, 1000);

        Benchmark(() => { var result = PrivacyPolicyLocaleFormatIsInvalidStatic("en-GB"); }, 1000);

        Benchmark(() => { var result = IsValidLocale("en-GB"); }, 1000);

    }

    private bool PrivacyPolicyLocaleFormatIsInvalid(string locale)

    {

        var regex = new Regex(@"^[A-z]{2}-[A-z]{2}$", RegexOptions.None, TimeSpan.FromSeconds(1)); //Regex: Two letters, one hyphen and two letters.

        if (regex.IsMatch(locale))

            return false;

        return true;

    }

    private static bool PrivacyPolicyLocaleFormatIsInvalidStatic(string locale)

    {

        var regex = new Regex(@"^[A-z]{2}-[A-z]{2}$", RegexOptions.None, TimeSpan.FromSeconds(1)); //Regex: Two letters, one hyphen and two letters.

        if (regex.IsMatch(locale))

            return false;

        return true;

    }

    public static bool IsValidLocale(string locale)

    {

        try

        {

            CultureInfo ci = new CultureInfo(locale);

            return true;

        }

        catch (CultureNotFoundException)

        {

            return false;

        }

    }

}